Award winning filmmaker Stephen Bannon introduces his Tea Party movie trilogy at the Virginia Tea Party Convention held at the Richmond Convention Center on Oct. 8, 2010 in Richmond, Va. Bannon was just named the Breitbart News executive chairman Chief Executive of Donald Trump's campaign. (Tina Fultz/Zuma Press/TNS)

WASHINGTON — Donald Trump’s effort to rebrand himself as a unifier and open-minded negotiator were drowned out by an angry national backlash over his naming of an enthusiastic promoter of white nationalism as his chief strategist in the White House.

The appointment of Breitbart News media executive Stephen K. Bannon, who served as CEO of Trump’s campaign, was met with dismay and loud rebuke from mainstream Jewish and Muslim groups, civil rights organizations and many Republicans. It leaves Republican congressional leaders who have been sanguine about Trump’s prospects for unifying the nation scrambling to shift the conversation — or at least to profess they don’t know about Bannon’s well-documented relationship with the far right.

And it quickly mobilized Democrats to warn that Trump is further empowering the hate groups rejoicing in his victory.

“It is a sad day when a man who presided over the premier website of the alt-right — a loose-knit group of white nationalists and unabashed anti-Semites and racists — is slated to be a senior staff member in the people’s house,” Anti-Defamation League CEO Jonathan Greenblatt said. The Southern Poverty Law Center said much the same, calling the Breitbart shaped by Bannon “the energy behind an avalanche of racist and anti-Semitic harassment that plagued social media platforms for the entire presidential campaign.”

GOP strategist John Weaver, who helped run the presidential campaign of Ohio Gov. John Kasich, tweeted that “the next president named a racist, anti-Semite as the co-equal of the chief of staff.” A poster on the neo-Nazi website Daily Stormer wrote: “Bannon is our man in the White House.”

Trump supporters scrambled to define Bannon as something other than the right-wing firebrand who turned Breitbart into what former staffer Ben Shapiro describes as a platform for “white ethnonationalism” and a “cesspool for white supremacist meme makers.”

“That’s not the Steve Bannon that I know and I’ve spent a lot of time with him,” said Reince Preibus, the Republican National Committee chairman who was named Trump’s chief of staff at the same time the Bannon appointment was announced Sunday. “Here’s a guy who’s a Harvard Business School, London School of Economics, 10-year Naval officer advising admirals. He was a force for good on the campaign at every level that I saw, all the time.”

Trump campaign manager Kellyanne Conway recited the same credentials during a short interview outside Trump Tower, additionally citing Bannon’s former job as a Goldman Sachs partner and his time in Hollywood. “Brilliant tactician,” she said.

But it was clear on Capitol Hill that Bannon represented the side of the Trump campaign Republicans struggled with during the general election, and which they have grown no more comfortable with now that Trump is about to assume power in the White House.

House Speaker Paul D. Ryan (R-Wis.) said on CNN that he does not have concerns because “I’ve never met the guy. … I trust Donald’s judgment.” House Majority Leader Kevin McCarthy (R-Bakersfield) told reporters it would be unfair to hold Bannon responsible for all the content produced by Breitbart.

But his imprimatur penetrates every aspect of its coverage, according to some of those who were on the Breitbart payroll as Bannon moved the site from a somewhat more traditionally conservative platform created by founder Andrew Breitbart to what Bannon boasted in July has now become “the platform for the alt-right.”

“He was the ideological driving force behind Breitbart and its content,” said GOP strategist Kurt Bardella, who said he talked to Bannon almost daily for two years while working as Breitbart’s media consultant. “He put himself front and center.”

“There was a big personality void when Andrew died,” said Bardella, a conservative who parted ways with Breitbart as the site became something he saw as “toxic and perpetually malcontent.”

“He was so synonymous with Breitbart. When Andrew went away, Steve stepped in and filled that void. How Breitbart evolved from then to now is a manifestation of that. He was very hands-on.”

Other employees have also left Breitbart, citing the same concerns as Bardella. And some journalists quit in protest in the spring after a Breitbart reporter accused Trump’s then-campaign manager of manhandling her at a political event and Breitbart responded by publishing an article doubting its own reporter’s claim.

Bannon’s personal life has been as stormy as his life in politics. An ex-wife accused him of attacking her in 1996, leading to charges of domestic violence, which were ultimately dismissed when prosecutors said they could not locate the accuser. Later, in 2007, during divorce proceedings, Bannon’s ex-wife alleged that he repeatedly made anti-Semitic remarks as the couple toured Los Angeles private schools for their daughters.

She said Bannon asked the director of the Westland School “why there were so many Hanukkah books in the library.” She said in court filings that he was concerned that the Willows Community School “used to be in a temple.” As the couple pondered the Archer School for Girls, Bannon’s ex-wife alleged in her deposition, he “went on to say the biggest problem he had with Archer is the number of Jews that attend. He said that he doesn’t like Jews and that he doesn’t like the way they raise their kids to be ‘whiny brats’ and that he didn’t want the girls going to school with Jews.”

Bannon, who ultimately sent his children to the Archer School for middle school and high school, has denied ever making any such comments.